Polishing translations

As I said in my [previous pull request](https://github.com/comfy/comfortable-mexican-sofa/pull/292), some things were not translated in the interface, so now they are. Not sure if it makes some tests fail, as I'm new to all of this stuff.

Do you know how to make bootstrapped-wysihtml5's locale depend on the site setting? [The translations are already available.](https://github.com/jhollingworth/bootstrap-wysihtml5/#i18n)